The present invention relates to a redundancy switching method.
General-purpose servers have been extensively used for service provisions in IP networks. Especially in a service whose stop is not allowed, an operation is performed by redundantizing a service provision server, in order to ensure a reliability. In such a redundantized configuration, in order that a client who receives the provision of the service may be prevented from becoming aware of the system switching between an operation system server and a standby system server, the change of IP addresses from the operation system server to the standby system server is required in case of the system switching between the general-purpose servers. Heretofore, JP-A-10-320323 (Patent Document 1) has stated a technique wherein an identical IP address can be simultaneously given to the operation system server and the standby system server by making a setting so as not to send back an ARP reply to the ARP handler of the standby system server, and the application of the standby system server can be prepared for the service provision in spite of a standby state, whereby the system switching is permitted in a short time.
Besides, JP-A-2004-171370 (Patent Document 2) has stated an IP floating system wherein two dualized servers are connected with a LAN by an identical floating IP address, and the server to become a standby state (standby system) validates the floating IP address, whereas the server to become a standby state (standby system) invalidates the floating IP address.